Hot-wire anemometry is used to study the origin and growth of natural fluctuations in zero pressure-gradient boundary layers for several Mach numbers between 1.6 8.5. The importance transition certain physical mechanisms examined through comparison fluctuation with sound-forcing stability theories Mack. Flow substantial amplitude were observed within laminar layer ahead stations where instability amplification expected be important. These found cross-correlated sound field higher supersonic...

Efficacy and safety of current means to prevent cerebrovascular thrombosis in patients at high risk stroke are suboptimal. In theory, anchoring fibrinolytic plasminogen activators the luminal surface cerebral endothelium might arrest formation occlusive clots this setting. We tested approach using recombinant construct antiplatelet-endothelial cell adhesion molecule (PECAM) single-chain variable fragment (scFv)-urokinase-type activator (uPA), fusing low-molecular-weight urokinase-type with a...

The Aircraft Laser Infrared Absorption Spectrometer (ALIAS) instrument is a high-resolution (0.0003 cm-(1)) scanning tunable-diode-laser spectrometer designed, tested, and flown more than 30 times on the National Aeronautics Space Administration's high-altitude ER-2 aircraft in Airborne Arctic Stratospheric Expedition of 1991-1992. Using long-path infrared laser absorption spectroscopy to detect optical absorptions as small 10-(5), ALIAS provides fast, continuous in-situ measurements key...

The high-amplitude, low-frequency, disturbances generated in a Blasius boundary layer by grid-produced freestream turbulence were studied means of hot-wire anemometry and flow visualization. Emphasis was placed on determining the cause nature these, their effect upon mean profile. It found that motion intrinsically three-dimensional, according to which fronts, Tollmien-Schlichting waves became warped. Evidence streamwise vorticity noted. At Reynolds numbers near 1.6 million, maximum...

Mathematical expressions are derived for the motion of a rigid, uniform sphere in an underwater sound field. The results show that at low frequencies neutrally buoyant this type has velocity equal to particle water same location when is removed. A pickup may be mounted inside such form hydrophone sensitive velocity. Two practical design applications presented. low-frequency with diameter five inches was constructed having essentially flat response between 15 and 700 cps sensitivity 0.18...

Two cavity-type radiometers have been developed, based on first principles, having the capability of measuring an irradiance with indicated error 0.3%. The prerequisites for this accuracy are a measured aperture area, measurement electric voltages, and effective absorptance its blackbody cavity from 0.998 to 0.999 throughout uv, visible, ir spectral ranges. radiometer is designed operate only in vacuum <10−5 Torr measure intensities 10 mW cm−1 300 cm−2. By using evacuated cold chamber,...

Free stream fluctuating pressures are determined from hot-wire measurements in a Mach 3.5 pilot quiet nozzle over unit Reynolds number range 10-60 million per meter. Further, the transition numbers on sharp tip 5 degree half-angle cone at zero angle of attack obtained same equilibrium temperature cone. Results show that provides noise levels upstream regions test rhombus substantially lower than conventional nozzles. The normalized rms static found to vary extremely low values less 0.03% up...

Spherical shells of submillimeter size are sought as ICF targets. Such must be dimensionally precise, smooth, high strength, and composed a atomic number material. We describe technology for the production based upon hydrodynamic instability an annular jet molten metal. have produced in 0.7–2.0 mm range using tin test Specimens exhibit good sphericity, fair concentricity, excellent finish over most surface. Work involving gold–lead–antimony alloy is progress. Droplets this amorphous possess...

Measurements relating to the noise source location and intensity within various frequency bands were made for an 0.75 m-chord wing/flap model installed in Ames 7 x 10-foot wind tunnel. A directional microphone system, located outside open-wall tunnel was scanned a two-dimensional array of aiming points about positive-pressure side determine principal locations production, each these. It found case flaps being differentially deflected (0 deg, 35 deg) at half-span station that production...

Wind tunnel studies have been conducted to determine the specific locations of aerodynamic noise production within flow field about various lifting-surface configurations. The models tested included low aspect ratio shapes intended represent aircraft flaps, a finite NACA 0012 wing, and multi-element wing section consisting main section, leading edge flap, dual trailing flaps. Turbulence was induced on by surface roughness. Lift drag were measured for flap models. Hot-wire anemometry used...

Hot-wire anemometry is used to study the origin and growth of 'natural' fluctuations in zero pressure gradient boundary layers location transition turbulence for several Mach numbers between 1.6 8.5. The importance certain physical mechanisms examined through comparison fluctuation with sound-forcing stability theories Mack. are shown assume varying low supersonic, high supersonic hypersonic regimes. effect on cone angle attack, tip heating, model vibration mentioned.

This paper considers only the simple part of Fourier Integral theory required for work in hand. A special type Henrici rolling sphere harmonic analyzer has been built which makes possible a large reduction amount labor involved dealing graphically with operations. Examples use this procedure as applied to several geophysical instrument problems are given.

Septic arthritis of the shoulder can destroy glenohumeral joint resulting in significant pain, instability and poor function. Surgical treatment is notoriously difficult with risk complications. Shoulder arthrodesis has been performed using both internal external fixation but high complication rates presence infection. We present our experience managing a patient pain loss function as result septic following infected proximal humeral fracture associated osteomyelitis. discuss presentation,...